In heaters used in vehicles, which may be operated, e.g., as parking heaters or auxiliary heaters, the fuel is taken up, in general, in a metering pump from a fuel tank via a suction line and is introduced by the metering pump under pressure into the combustion chamber of the heating burner via a pressure pipe. To ignite the fuel introduced into the combustion chamber, e.g., by evaporation or atomization together with the combustion air, which is likewise introduced, at the beginning of a phase of operation, e.g., an igniting member designed as a glow-type ignition pin is provided.
The problem arises during the operation of such systems that fuel is still present in the line section between the metering pump and the combustion chamber on switching off, and this fuel still evaporates at least in the area of the pressure pipe close to the combustion chamber with the ignition stopped and thus leads to emissions that are potentially hazardous as to ones health. A generally asymmetric feed of the fuel into the combustion chamber during the operation leads to a combustion that is not distributed uniformly over the combustion chamber, as a consequence of which the combustion does not take place in the optimal lambda range in all areas of the combustion chamber, which may lead to the formation of deposits.